Method of pressing dough portions

ABSTRACT

The invention provides a press for bread products which includes two horizontally opposed, inclined press blocks which contain electromagnets with a trapezoidal pendulum block is pivotally mounted between the press blocks. The pendulum includes two large permanent magnets. The polarity of the electromagnets is switched in a manner to force the pendulum to swing from contact with one press block to the other. A dough ball distribution system is also provided which distributes dough balls to interstitial positions between the pendulum and the press blocks, so that when the polarity of the electromagnets is switched, the pendulum press block presses the dough ball into a tortilla. A heating system is provided to heat the press blocks and pendulum block to partially cook the tortilla and aid in removing the pressed blocks after it is pressed. Controlling circuitry is also provided which controls the activation of the heating system, the motion of the press block, the timing between the dough ball distributor and movement of the pendulum press block.

This is a divisional of application Ser. No. 08/905,591 filed Aug. 4,1997 now U.S. Pat. No. 5,937,739.

TECHNICAL FIELD

This invention relates generally to machines for making tortillas, andparticularly concerns an automatic machine for pressing and partiallycooking tortillas.

BACKGROUND ART

The rapid rise in popularity of Mexican food has created a need formedium capacity tortilla machines that can be used in a restaurantenvironment. These machines process and cook, to a varying degree,tortilla dough portions into tortillas. In some cases, other flat breadproducts such as pizza shells are pressed and cooked as well.

Several prior art examples exist which illustrate the mechanization ofthe tortilla making process. The invention described in U.S. Pat. No.4,683,813 to Schultz employs a press mechanism which provides for asynchronized pressing motion between a press plate and a rotatingcooking disk. The disk rotates in a horizontal plane while the platemoves in a vertical plane. The synchronized motion is accomplished by aseries of gears, extension arms, and drive shafts.

Another example is disclosed in U.S. Pat. No. 4,508,025 to Schultz.Here, a flat plate is pulled down against a stationary platen by anarrangement of cams, extension arms, and springs, thereby pressing adough ball into a round flat shape.

A third example can be found in U.S. Pat. No. 4,838,153 to Ischiomeli etal. The invention disclosed in Ischiomeli pivots one heated platenupward against another. Both of the platens are at an angle relative tothe horizontal. As a result, after a tortilla is pressed, it slidesdownward due to the force of gravity alone.

None of these inventions have proved to be completely satisfactory. Eachhas an abundance of moving parts which are difficult to clean, difficultto service, and difficult to maintain. Also, the mechanisms used torelease the tortilla from the pressing platens are not completelyeffective, resulting in the dough sticking to the platens and othercleaning and mechanical problems. Additionally, the degree to which thebread product is toasted by each of the prior art mechanisms requirestime consuming or complex mechanical adjustments. Finally, each of theprior inventions require mechanical adjustment in order to set and resetthe thickness of the tortilla.

SUMMARY OF THE INVENTION

The preferred embodiment of the invention includes a press mounted in asteel enclosure having a removable top. An entrance port in theremovable top allows admittance of dough balls, and a slot in the bottomof the enclosure provides an exit for tortillas.

Inside the enclosure, two opposing stationary press blocks arepositioned above the slot in the bottom of the enclosure. The inner faceof each stationary press block is angled to form an inclined plane, thebottom of which is aligned with the slot in the bottom of the enclosure.

The stationary press blocks are constructed of a ceramic material, and asteel plate is embedded in the inner face of each block. Within eachstationary press block, a coercive element such as a relatively largeelectromagnet is positioned so that one of its magnetic poles is incontact with the steel plate. Each stationary press block also containstwo internal rod-type electrical heating elements and two longitudinalholes to heat the block.

A generally trapezoidal movable press block is positioned between thestationary press blocks. The movable press block is constructed of thesame ceramic material as the stationary press blocks. Two opposing pressfaces of the movable press block are at generally the same inclinedangle as the corresponding opposing faces of stationary press blocks. Asingle support plate extending from the bottom of the movable pressblock is pivotally and removably positioned above and parallel to thecentral longitudinal axis of the slot in the bottom of the enclosure.

A steel plate is imbedded in the surface of each of the press faces ofthe movable press block. Two large permanent magnets are positionedwithin the movable press block directly adjacent to and in contact witheach steel plate. The magnets are arranged so that the north pole of onemagnet is in contact with one steel plate and the south pole of theother magnet is in contact with the other steel plate.

A ducting system is included which redirects hot air off of heated grillsurface through the holes in the stationary press blocks and downwardover their faces in order to maintain the press blocks at a uniformtemperature efficiently and aid in lifting and removing partially cookedtortillas from the stationary press blocks after they have been pressed.To further aid in removing the partially cooked tortillas, each steelplate may be coated with Teflon to reduce friction between the tortillaand plate.

A feeder assembly is provided to deliver dough balls to the press. Thefeeder assembly is supported by a frame that is removably attached tothe steel enclosure in which the press is mounted. The frame supportstwo sprockets that, in turn, support a drive chain. A series of cups forholding dough balls are attached to the drive chain at regularintervals.

A ratchet mechanism is attached to one of the sprockets in order todrive the chain and the cups about the sprockets. An electric solenoiddrives the ratchet assembly. Each time the solenoid actuated, the chaintips a cup to a vertical position and drops a dough ball into theentrance port in the top of the enclosure. The feeder assembly ispositioned so that the cup becomes vertical directly above the entranceport in the lid of the steel enclosure.

A timer is used to alternately switch the polarity of the currentapplied to the electromagnets in the stationary press blocks. Bothelectromagnets are connected to have the same polarity. Therefore, whencurrent is supplied to the electromagnets, the permanent magnets in themovable press block are repelled on one side and attracted on the otherside, forcing a pivotal movement of the movable press block from a firstposition close to one stationary press block to a second position closeto the other stationary press block, or vice versa. At approximately thesame time, the solenoid is actuated, thereby advancing the chain andtipping a cup.

In operation, uncooked dough balls are placed in the cups. A timeractivates the solenoid and switches the polarity of the electromagnetsin the stationary press blocks. The solenoid advances the chain and tipsa cup over the entrance port in the top of the steel enclosure. Thedough ball from the cup drops through the entrance port and rolls to oneside or the other of the movable press block, depending on the positionof the movable press block, and finally lodges in the interstitialposition between one steel plate of the movable press block and thesteel plate imbedded in the first stationary press block.

After a predetermined interval, the timer again activates the solenoidand reverses the polarity of the current supplied to the electromagnetsin the stationary press block, causing the movable press block to pivottoward the first stationary press block and a second dough ball to fallout of a cup. As the movable press block pivots, the dough ball betweenthe movable press block and the first stationary press block is pressedinto a flat, circular shape, i.e., a tortilla. A second dough ballsimultaneously rolls to the interstitial position between the movablepress block and the second stationary press block. For a predeterminedinterval, the tortilla is toasted by heat from the first stationarypress block and the movable press block. After that interval, the cyclerepeats.

As the movable press bock pivots toward the second stationary pressblock, the toasted tortilla is lifted off of the face of the firststationary press block by hot air from the ducting system and gravitycauses it to drop through the bottom slot onto a grill surface for finalcooking.

The present invention has readily apparent advantages over the priorart. For instance, when pressing a dough ball into a tortilla, themagnetic forces are evenly distributed along the press face of themovable press block and the press face of the corresponding stationarypress block. As a result, the force is applied evenly to the dough ball,thereby producing a tortilla having a substantially constant thickness.To adjust the thickness of the tortilla, one need only adjust thevoltage supplied to the electromagnets.

Additionally, the press of the present invention has very few movingparts to clean or maintain; therefore, cleaning the press is extremelysimple. The lid of the enclosure is removed, and the movable press blockis removed by merely lifting it out of the enclosure. The movable pressblock and the stationary press blocks are then readily accessible forcleaning.

Additionally, the use of redirected air through a novel ducting systemefficiently maintains constant heat throughout the apparatus as well asaiding in removal of the tortilla from the contact surfaces after it hasbeen partially cooked.

Further, the degree in which the tortilla is toasted is easilycontrolled by setting the predetermined time interval on the timerobviating the need for changing motor speeds, gears or other mechanicalsettings as is required by the prior art.

Other advantages will be apparent to those skilled in the art afterreviewing the description of the preferred embodiment and the attacheddrawings which illustrate it.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the invention will be described in detail withreference to the attached drawings in which:

FIG. 1 is a sectional front view of a bidirectional magnetic ceramictortilla press in accordance with the invention;

FIG. 2 is a side view of the tortilla press of FIG. 1;

FIG. 3 is a schematic diagram of the control circuit for the tortillapress of FIG. 1; and

FIG. 4 is a timing diagram illustrating the timing relationship ofselected signals of the control circuit of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1 and 2 illustrate a preferred embodiment of a bidirectionalmagnetic ceramic tortilla press 10 in accordance with the invention.Square steel enclosure 12 serves to house and support the internalcomponents of the press 10. Enclosure 12 includes bottom 14 having slot16 therein and open top 18. Top 18 of enclosure 12 is fitted withremovable lid 20 that includes entrance port 22 that is disposeddirectly over slot 16 when lid 20 is installed on top 18 of enclosure12.

Although enclosure 12 of the preferred embodiment is constructed ofsteel, it will be appreciated that other materials could be used, suchas aluminum, stainless steel, or high temperature plastic.

Two stationary press blocks 24, 26 are removably mounted withinenclosure 12 by bolts 28. As best seen in FIG. 1, a lower, inner edge30,32 of each stationary press block 24, 26 is parallel to slot 16 inbottom 14 of enclosure 12.

In the preferred embodiment of the invention, the stationary pressblocks 24, 26 are constructed of a ceramic kiln brick material. Otherceramic or non-magnetic materials, such as cast aluminum, may also beemployed.

Each stationary press block 24, 26 is shaped so that inner face 34, 36of each forms an inclined plane that is parallel to slot 16. Inner faces34, 36 of stationary blocks 24, 26 extend from adjacent to opposed sidesof top 18 of enclosure 12 to immediately above slot 16 in bottom 14 ofenclosure 12.

Each stationary press block 24, 26 is solid with the exception of twosets of longitudinal holes 38, 40, 42, 44 extending parallel to innerface 34, 36. One set of holes 38, 42 serves as ducts through which hotair is passed to heat stationary blocks 24, 26, as will be describedbelow. Each of the other set of holes 40, 44 contains an electricalrod-type heater 46. Rod-type heaters 46 are used to pre-heat andmaintain stationary press blocks 24, 26 at operating temperature. In analternate embodiment, holes 38 and 42 are not present. The operatingtemperature of the blocks are maintained solely by electrical heatersformed integrally in the blocks (not shown) or by the proximity of theblocks to other heated elements of the apparatus.

Steel plate 48, 50 is embedded in inner face 34, 36 of each stationarypress block 24, 26. Each steel plate 48, 50 may also be coated with aTeflon surface to aid in reducing friction between toasted tortillas andthe plate itself; thereby aiding in the removal of toasted tortillas.Mounting bolts 28 are also imbedded in stationary press blocks 24, 26.Mounting bolts 28 are arranged to pass through corresponding holes 52 inenclosure 12. Nuts (not shown) are installed on bolts 28, firmlyaffixing stationary press blocks 24, 26 to enclosure 12. It will beappreciated that stationary press blocks 24, 26 are easily removablefrom enclosure 12 for cleaning and maintenance.

Also embedded in each stationary press block 24, 26, beneath inner face34, 36, is an electromagnet 56, 58. Each electromagnet 56, 58 is indirect contact with the corresponding steel plate 48, 50 embedded in theinner face 34, 36 of stationary press block 24, 26. In the preferredembodiment of the invention, electromagnets 56 and 58 are part number012, offered by Magnetic Technologies, Boxne City, Mich. Each is ratedat 72 watts at twelve volts, and is constructed to withstand continuoususe at over 425°, that is, over the operational temperature of theinvention. Each magnet is capable of supporting 1,050 pounds whensupplied with current. Of course, other electromagnets of varying sizesand ratings are available that can fulfill the function ofelectromagnets 56, 58.

Movable press block 60 is pivotally mounted between stationary pressblocks 24, 26. In the preferred embodiment, movable press block 60 isconstructed of the same ceramic material as stationary press blocks 24,26. Movable press block 60 is generally trapezoidal in shape and issupported above slot 16 by suspension plate 62 which is embeddedvertically in the bottom movable press block 60 parallel to the longaxis of the trapezoid. Suspension plate 62 is slightly longer than slot16, so it extends above the central longitudinal axis of slot 16 and ispivotally supported at each end of the slot 16 by the bottom 14 of theenclosure 12.

Movable press block 60 has two downwardly facing angled press faces 64,66. A steel plate 68, 70 is embedded in each press face 64, 66, andbelow each steel plate 68, 70 a permanent magnet 72, 74 is embedded.Each steel plate 48, 50 may also be coated with a Teflon surface to aidin reducing friction between toasted tortillas and the plate itself;thereby aiding in the removal of toasted tortillas. In the preferredembodiment, one permanent magnet 72 is embedded with its north polefacing outwardly from movable press block 60, and the other permanentmagnet 74 is embedded with its south pole facing outwardly. Two shuttlesurfaces 74, 76 at the top of the movable press block 60 form an apexthat is positioned directly below entry port 22 in the lid 20 ofenclosure 12.

In another embodiment, movable press block 60 has embedded in it twoelectromagnets in place of permanent magnets 72, 74. In this embodiment,current is supplied to the electromagnets in movable press block 60 viarelay 406 as will be described in more detail later.

In another embodiment, movable press block 60 has embedded in it, onepermanent magnet centrally disposed between steel plates 68, 70. In thisembodiment, movable press block 60 is constructed so that the singlepress block magnet is held in contact with both plates through a centralcavity in movable press block 60 (not shown).

In another embodiment, the movable press block has embedded in it, oneelectromagnet centrally disposed between steel plate 68, 70. In thisembodiment, movable press block 60 is constructed so that the singleelectromagnet is held in contact with both plates through a centralcavity in movable press block 60 (not shown). In this embodiment, thesingle electromagnet is supplied with current of one polarity via powersupply 402 which does not change during operation of the press.

Movable press block 60 is free to pivot between two positions inrelation to stationary press blocks 24, 26. When in the left position asshown in FIG. 1, the left press face 64 of movable press block 60 isimmediately adjacent and substantially parallel to steel plate 48embedded in the inner face 34 of left stationary press block 24. When inthe right position (not shown), right press face 66 of movable pressblock 60 is immediately adjacent and substantially parallel to steelplate 50 embedded in inner face 36 of right stationary press block 26.

A pair of rod-type heaters 80 are disposed within two centrally locatedlongitudinal holes 82 in movable press block 60. In the preferredembodiment of the invention, the rod-type heaters 80 employed aremanufactured by Chromalloy Corporation of Tennessee, and are used topreheat and maintain movable press block 60 at operating temperature. Ofcourse, other similar heaters may be employed. In an alternateembodiment, holes 82 and rod-type heaters are not present in movablepress block 60. In this embodiment, the proper operating temperature ofmovable press block 60 is maintained by its close proximity to andcontact with other heated elements of the invention.

As shown in FIG. 2, in the preferred embodiment of the invention, press10 is located closely adjacent to heated grill surface 202. Heated airfrom this grill surface is used to heat the stationary press blocks. Aducting systems is supplied to accomplish this. Intake duct 204 isthreaded into a first manifold 206 that is attached to enclosure 12.Directly adjacent to each longitudinal hole 38, 42 in stationary pressblocks 24, 26 is hole 208 through the wall of enclosure 12 that is influid communication with first manifold 206.

Second set of holes 212 in enclosure 12 at the other end of longitudinalholes 38, 42 in stationary press blocks 24, 26 are in fluidcommunication with second manifold 214. Second manifold 214 directs airinto the intake of impeller 216. The output of impeller 216 is held inducted communication with third manifold 218. Third manifold 218 splitsinto right arm 224 and left arm 220, which both extend the length ofpress enclosure 12 and include a plurality of nozzles 222, 223. Nozzles222, 223 are arranged to direct heated air downwardly over inner faces34, 36 of stationary press blocks 24, 26. When activated, impeller 216draws heated air from adjacent grill surface 202 through intake duct204, manifold 206, longitudinal holes 32, 38 into second manifold 214.Impeller 216 then forces heated air upward into third manifold 218 andon into right arm 224 and left arm 220 to be distributed throughplurality of nozzles 222, 223. Thus, heated air from grill surface 202is used to evenly and efficiently heat the stationary press blocks 24,26 from both the inside and the outside, thereby decreasing theelectricity consumed in heating them with rod-type heaters 80.Additionally, heated air from the nozzles 222 and 223 aids in liftingand pushing partially cooked tortillas off of stationary press blocks 24and 26 thereby avoiding previously encountered sticking problems.

In order to supply dough balls to the press, feeder assembly 300 isprovided. Feeder assembly 300 is removably attached to enclosure 12 byconventional means. Feeder assembly 300 is supported by two parallelplates 304, 306. In the preferred embodiment of the invention, plates304, 306 are constructed from machined aluminum, but they could also bemade of steel, heat resistant plastic, or other rigid materials. Each ofplates 304, 306 includes two holes 308, 310, one adjacent to either end.The holes 308, 310 in each plate 304, 306 are aligned with thecorresponding holes 308, 310 in the other plate 304, 306. Two sets ofrotary bearings (not shown) are pressed into holes 308, 310. Thebearings support two shafts 316, 318. The shafts 316, 318 supportsprockets 320, 322. Steel link chain 324 is fitted around sprockets 320,322, and plurality of stainless steel cups 326 are attached along chain324 at regular intervals. Each cup 326 is riveted to a single link ofchain 324, so that the attachment of cups 326 does not interfere withthe rotation of the chain 324 around sprockets 320, 322.

As best seen in FIG. 2, shaft 316 extends outwardly beyond plate 306 andis attached to single-direction rachet assembly 328. Single-directionratchet assembly 328 allows shaft 316 to rotate only in clockwisedirection as viewed in FIG. 1. Ratchet assembly 328 is attached topiston 330 of solenoid 332 by first pivot pin 334. Solenoid coil 336 ofsolenoid 332 is attached to plate 306 by second pivot pin 338. Whenelectrical current is applied to the solenoid coil 336, solenoid piston330 moves upwardly as viewed in FIG. 1, causing the ratchet assembly 328to rotate shaft 316 clockwise. When electrical current is removed fromthe solenoid coil 336, the piston 330 retracts, but the ratchet assembly328 does not rotate shaft 316 counterclockwise. Thus, solenoid 332 andratchet assembly 328 cooperate to rotate shaft 316 incrementallyclockwise, thereby causing the chain 324 to advance in steps.

It should be recognized that other methods of advancing sprockets 320,322 such as an electrically-controlled stepper motor (not shown) orpneumatic cylinders (not shown) with appropriate controls, or manualfeeder assemblies (not shown) can also be employed in other embodimentsof the invention with equal success.

FIG. 3 is a schematic diagram of controller 400 that controls thefunctions of tortilla press 10. Controller 400 consists of power supply402, timer 404, relay 406, and logic circuit 410.

In the preferred embodiment, power supply 402 is connected throughmaster switch 412 to 115 volts A.C. Power supply 402 supplies regulated12 volt D.C. and regulated 5 volt D.C. power at 5 amps maximumcontinuous current. In the preferred embodiment, a Minarc Corporation ofGlendale, Calif., Model XPF5-115AC is employed. As will be apparent tothose skilled in the art, other power supplies providing similar voltageand current can be substituted for this one. Additionally, powersupplies with variable output can be used to adjust the intensity of themagnetic field radiated by electromagnets 56, 58. If a variable powersupply is used, the result is that the pressing force of the movablepress block against the stationary press block, in either orientation,can vary. This results in a variable size and thickness of tortilla bysimply adjusting the current of the power supply. This is a majoradvantage over the prior art because it requires no mechanicaladjustments and can be accomplished very quickly without interruptingoperation of the invention.

Also connected to 115 volts A.C. through master switch 412 are rod-typeelectrical heaters 46, 80 in stationary press blocks 24, 26 and movablepress block 60 and impeller 216.

Power supply 402 provides 12 volt D.C. power for electromagnets 56, 58through double-pole, double-throw relay 406. Relay 406 is connected sothat when it is energized, electromagnets 56, 58 receive current flowingin one direction, and when it is de-energized, electromagnets 56, 58receive current forming in the other direction. The parallel connectionbetween relay 406 and electromagnets 56, 58 forces the polarity of theelectromagnets to be the same for any given signal from relay 406. Inthe "on" segments, relay 406 is energized. In the "off" segments, relay406 is deenergized. Timer 404 provides the signal that energizes andde-energizes relay 406 and the input to logic unit 410.

FIG. 4(a) represents the timer signal that controls relay 406 and whichis input to logic unit 410. As can be seen, the signal consists of equal"on" (T1) and "off" (T2) segments, corresponding to T1,500 and T2,502.In the preferred embodiment, T1 and T2 are both set at 5 seconds,although the times can be easily adjusted by adjusting timer 404 asdesired. Shorter times for T1 and T2 result in shorter cooking times forthe tortilla, longer times for T1 and T2 result in longer cooking times.

Timer 404 also provides the signal that is the input to logic unit 410.Logic unit 410 consists of a transistor triggering circuit and an RCtimer which are well known in the art and therefore will not bedescribed in detail here.

FIG. 4(b) represents the signal produced by the logic circuit 410. The"on" (T3) segments of the logic circuit output are triggered by bothleading edge 500 and trailing edge 502 of the timer signal (shown inFIG. 4(a)) that controls electromagnets 56, 58. The logic circuit outputis connected to solenoid coil 336 and is of sufficient current to drivethe solenoid; therefore, each time the polarity of the current toelectromagnets 56, 58 is reversed by relay 406, a pulse is supplied tosolenoid coil 336 by logic unit 410, the energized coil extends solenoidpiston 330 and advances chain 324, thereby dropping a dough ball Bthrough entrance port 22 of tortilla press 10.

The operation of the preferred embodiment of the present invention willnow be described. In operation, the machine is placed near the heatedgrill surface 202. Before operation is begun, the heated grill surfacemust reach its operational temperature, usually about 425° F. At thispoint, master switch 412 is thrown, activating heaters 46 and 80,impeller 216, timer 404, and power supply 402. Heaters 46 and 80 areallowed to rise to their operational temperature, about 425° F., withthe aid of heated air drawn through holes 38, 42. Impeller 216, afteractivation, draws heated air from grill surface 202, through duct 210,and through holes 38, 42. The hot air from heated grill surface 202raises the temperature of the stationary press blocks to approximately425°. The hot air is drawn through impeller 216 and upward throughmanifold 220, being distributed through arms 220 and 224, to nozzles 222and 224.

After operational temperature is reached, dough ball B is manuallyplaced in the upwardly facing cups 326 of feeder assembly 300. Timer 404then activates relay 406. Activating relay 406 reverses the polarity ofthe current applied to electromagnets 56, 58. As a result, the magneticpolarity of electromagnets 56, 58 is also reversed. For instance, asshown in FIG. 1, the pole of each electromagnet facing the movable pressblock is north. After the current is reversed by relay 406, leftelectromagnet 58 repels the north pole of permanent magnet 72 and theleft face 64 of movable press block 60, and right electromagnet 58attracts south pole of magnet 74 in right face 66 of movable press block60. Thus, movable press block 60 is moved to the right magnetically.Simultaneously, the signal from timer 406 causes logic unit 410 toproduce pulse T3. Pulse T3 activates solenoid coil 336, which advanceschain 324, causing rightmost upwardly facing cup 326 (as viewed inFIG. 1) to rotate to a vertical position over entry port 22 in lid 20 ofenclosure 12, thereby dropping a dough ball B through entry port 22. Inthe preferred embodiment, the upward movement of solenoid piston 330takes longer than the arcuate movement of the movable press block fromone position to the other; therefore, movable press block 60 will haveswitched places before dough ball B falls onto either shuttle surface74, 76 of movable press block 60, in each pressing cycle. For instance,if movable press block 60 comes to rest in the left position as shown inFIG. 1, dough ball B will be deflected to the right by right shuttlesurface 76 of movable press block 60, thereby causing dough ball B tofall between right press face 66 of movable press block 60 and innerface 36 of right stationary press block 26.

After time T1 as shown in FIG. 4(a), timer 404 deactivates relay 406. Asa result, the polarity of the electrical current supplied toelectromagnets 56, 58 is again reversed, causing the pole of eachelectromagnet 56, 58 facing the movable press block to now become south.Thus, electromagnet 58 in right stationary press block 26 repelspermanent magnet 74 in right face 66 of movable press block 60, and leftelectromagnet 56 attracts permanent magnet 72 in left face 64 of movablepress block 60. This causes movable press block 60 to pivot to the leftposition, pressing waiting dough ball B into tortilla T. Tortilla T isthen pressed and toasted for the duration of time T2. At the same time,timer 404 causes logic unit 410 to send another pulse to solenoid 336.Solenoid coil 336, in turn, causes another dough ball B to be droppedthrough empty port 22 and lid 20 of enclosure 12. As movable press block60 is in the right position, dough ball B is deflected to the leftbetween left face 64 of movable press block 60 and interface 34 of leftstationary press block 24.

Due to the inclination of the inner face 36 of the right stationarypress block 26, and the heated air that is blown from the nozzles 222,224, the toasted tortilla slides downwardly through the slot 16 in thebottom 14 of the enclosure 12 and onto grill surface 202. As the movablepress block 60 moves to the left, current is supplied to the solenoidcoil 336, advancing the chain 324 and dropping another dough ball, B,beginning process described above again.

After time T2, as shown in FIG. 4B, timer 404 then reactivates relay406, thereby reversing the polarity of the current suppliedelectromagnets 56, 68. Movable press block 60 then swings from right toleft as shown in FIG. 1, thereby releasing the press tortilla on theright face of stationary press block 26 and pressing the waiting doughball between the face of stationary press block 24 and the left face 64of movable press block 60. This cycle repeats until switch 412 isopened, stopping operation of tortilla press 10.

Although the invention has been described of terms of specifiedembodiments which are set forth in detail, it should be understood thatthis by illustration only and that the invention is not necessarilylimited thereto, since alternative embodiments and operating techniqueswill become apparent to those skilled in the art in view of thedisclosure. Accordingly, modifications are contemplated which can bemade without departing from the spirit of the described invention.

What is claimed is:
 1. A method of pressing deformable dough portionscomprising the steps of:providing a pair of opposing platens; providinga central press block positioned between the platens; providing acoercive element, attached to the platens, to alternately urge the pressplate toward each platen; placing a dough portion between the pressblock and the first platen; cycling the press block toward the firstplaten; placing a second dough portion between the press block and thesecond platen; and cycling the press block toward the second platen. 2.The method of claim 1 further comprising the step of heating theplatens.
 3. The method of claim 1 further comprising the stepsof:providing a source of air pressure; and directing the air pressuretoward each of the platens.
 4. The method of claim 1 including the stepof:providing said coercive element as an electromagnet.
 5. The methodset forth in claim 4 wherein:the step of cycling said press blockcomprises energizing said electromagnet with current of one polarity. 6.The method set forth in claim 5 wherein:the step of cycling said pressblock comprises reversing the polarity of current energizing saidelectromagnet.
 7. The method set forth in claim 1 including the stepof:placing said dough portion between said press block and said firstplaten in timed relationship to energizing said coercive element.
 8. Themethod set forth in claim 1 including the step of:providing saidcoercive element as electromagnets in each of said platens andenergizing said electromagnets with current flowing in one direction tocycle said press block toward said first platen and then energizing saidelectromagnets with current in another direction to cycle said pressblock toward said second platen.
 9. The method set forth in claim 8including the step of:timing the placement of a dough portion betweensaid press block and said platens, respectively, in relation toenergizing said electromagnets.
 10. The method set forth in claim 1further comprising the step of:heating said platens with hot airdirected toward said platens, respectively.
 11. The method set forth inclaim 1 including the step of:heating said platens with electricalheaters disposed adjacent said platens.
 12. The method set forth inclaim 1 including the step of:heating said platens with electricalheaters formed integrally with said platens.
 13. The method set forth inclaim 1 including the step of:placing a low friction coating oncooperating surfaces of said press block and said platens to reducefriction between said dough portions and said surfaces, respectively.14. The method set forth in claim 13 wherein:the step of placing saidcoating comprises coating said surfaces with polytetrafluoroethylene.15. The method set forth in claim 1 including the step of:placing doughportions between said press block and said platens, respectively, with afeeder assembly.
 16. The method set forth in claim 15 wherein:said doughportions are placed between said press block and said platens bydispensing said dough portions, respectively, from plural cups of saidfeeder assembly.
 17. The method set forth in claim 1 wherein:the step ofplacing said dough portion between said press block and said firstplaten comprises dropping said dough portion onto a first surface ofsaid press block for guiding said dough portion into a position betweensaid press block and said first platen; and the step of placing saidsecond dough portion between said press block and said second platencomprises dropping a dough portion onto a second surface of said pressblock for guiding said second dough portion to a position between saidpress block and said second platen.
 18. A method of pressing deformabledough portions into flat dough products comprising the stepsof:providing an apparatus including a pair of opposed platens, a centralpress block disposed between said platens and movable toward and awayfrom each of said platens and a coercive element operable to alternatelyurge said press block toward each of said platens; placing a first doughportion between said press block and one of said platens and causingsaid coercive element to move said press block toward said one platen toflatten said first dough portion; and placing a second dough portionbetween said press block and the other of said platens and causing saidcoercive element to move said press block toward said other platen toflatten said second dough portion.
 19. The method set forth in claim 18including the step of:providing a feeder assembly disposed adjacent saidapparatus for feeding said dough portions seriatim to said apparatus forplacement between said press block and said platens, respectively. 20.The method set forth in claim 18 including the step of:providing saidcoercive element as magnetic means for moving said press block from afirst pressing position close to one of said platens to a secondpressing position close to the other of said platens.
 21. The method setforth in claim 20 including the step of:providing said magnetic means asat least one permanent magnet connected to said press block andproviding electromagnets connected to each of said platens,respectively.
 22. The method set forth in claim 21 including the stepof:energizing each of said electromagnets to cause said press block tomove toward said first platen and said second platen, respectively, topress said dough portions between said press block and said platens,respectively.
 23. The method set forth in claim 22 including the stepof:timing the placement of dough portions between said press block andsaid platens, respectively, in relation to energizing saidelectromagnets.
 24. The method set forth in claim 18 wherein:the step ofplacing said dough portion between said press block and said one platencomprises placing said dough portion on a first surface of said pressblock for guiding said dough portion into a position between said pressblock and said one platen; and the step of placing said second doughportion between said press block and said other platen comprises placinga dough portion on a second surface of said press block for guiding saidsecond dough portion to a position between said press block and saidother platen.
 25. A method of pressing deformable dough portions intoflat dough products comprising the steps of:providing an apparatusincluding first and second opposed platens, a central press blockdisposed between said platens and movable toward and away from each ofsaid platens, said press block including first and second guide surfacesfor guiding dough portions to positions between said press block andsaid platens, respectively, a coercive element operable to alternatelyurge said press block toward each platen and a feeder assembly disposedadjacent said apparatus for feeding dough portions seriatim to saidpress block for placement between said press block and said platens,respectively, as guided by said guide surfaces on said press block,respectively; energizing said coercive element to cause said press blockto move toward said first platen and said second platen, respectively,to press dough portions between said press block and said platens,respectively; and timing the feeding of said dough portions to saidpress block for placement between said press block and said platens,respectively, in relation to energizing said coercive element.